Wearing part for internal combustion engines



April 24, 1934-. c; K ET AL 1,956,014

WEARING PART FOR INTERNAL COMBUSTION ENGINES Original Filed Nov. 22.1924 IIIIIIIIII m. v F66 42M wwi Patented Apr. 24, 1934 PATENT OFFICEWEARING PART FOR INTERNAL COIWBUSTION ENGINES Colin G. Fink, New York,N. Y., and Charles H. Eldridge, Detroit, Mich, assignors, by mesneassignments, to Chemical Treatment Company, Inc., New York, N. Y., acorporation of New York Application November 22, 1924, Serial No.751,692

' Renewed December 6, 1933 4 Claims.

This invention relates to improvements in wearing parts, for internalcombustion engines. By wearing parts we mean parts that in the operationof the engine are subjected to wear as the result of impact, friction,exposure to the combustion gases, or the like. Thus, we intend toembrace in the term wearing parts such articles as valve parts(including heads, stems and seats), tappets, cam-followers, pistonrings, piston pins, channels, pipes, cylinder Walls, etc.

The invention aims to provide, as new articles of manufacture, improvedwearing parts, for internal combustion engines, and especially forautomotive engines. In accordance with the invention such wearing partshave at least a portion of their wearing surface covered withelectrodeposited chromium.

Several embodiments of the invention, by way of example, .areillustrated in the accompanying drawing, wherein Fig. l is a view partlyin elevation and partly in section of an automobile valve according tothe present invention;

Fig. 2 is a sectional view on the line IIII Fig. l.

Fig. 3 is a view in elevation of a piston pin according to theinvention.

Fig. e is a cross-section of Fig. 3 on the line IV.

Fig. 5 is a plan view of a piston ring according to the invention.

Fig. 6 is a view partly in side elevation, and partly in section, thesection being on the line VIVI Fig. 5.

Fig. 7 is a vertical cross-sectionof part of an internal combustionengine showing a poppet valve according to this invention, in theexhaust passage of the engine.

Referring to said drawing letter A designates the wearing part, andletter C the chromium electroplated thereon. The thickness of thechromium plate is exaggerated in the drawing.

In-Fig. 7 the poppet valve shown in Figs. 1 and 2, is shown as mountedin a conventional manner in an exhaust passage E of an internalcombustion engine, R being the bearing and S the seat.

In accordance with our present invention, the

wearing part A, for example a valve part, has its wearing surfacecovered to an appropriate extent with a relatively thin layer or film Cof electro-deposited chromium. By wearing surface, we

mean that portion of the-wearing part that is sub jected to wear as aresult of impact, friction, ex-

posure to the combustion gases, or the like. If desired, the entiresurface of the wearing part A may be covered with electro-depositedchromium 0. Where it is not necessary or not desirable to cover theentire surface of the wearing part with chromium, the inventioncontemplates covering with chromium such portion of the surface as isexposed to the greatest wear.

We have found that wearing parts for internal combustion engines whenprovided with chromium-plated surfaces in accordance with our presentinvention possess superior wearing qualities. In particular, suchchromium-plated wearing parts have a harder and longer wearing surface,as compared with similar unplated parts and consequently thechromium-plated parts of the invention are found to wear better and lastlonger.

The sulphur or sulphur compounds contained in oil attack most metals inwhich they come into contact, but this attack is not ordinarily noticedor accounted a factor in the wear of these parts, as the friction ofother parts, of the fluid streams, etc., on such parts is ordinarilyregarded as the principal cause of wear, and, moreover, the frictionusually keeps the parts bright, so that the cause of deterioration orwear is not readily apparent. Nevertheless, the softening of the surfaceby corrosion or attack is an important factor in the wear produced bythe friction of other parts and of liquid or gaseous streams on suchattacked surface. Chromium is unaffected by sulphur or sulphurcompounds, and hence chromium surfaced parts, while not only presentingharder surfaces for wear than hardened steel, are resistant to sulphurattack, and therefore give superior wear for both reasons.

Chromium-plated valve parts of the invention have hard surfacesresistant to impact, to friction and to the combined corrosive anderosive action of superheated exhaust gases moving at high velocity andto the corrosive contents of oil, such as sulphur or sulphur compounds.Tappets are used to operate the valves and when chromium-plated, inaccordance with the invention, possess a hard surface and are highlyresistant to impact.

In making the improved wearing parts A of the invention, the unplated'part may be manufactuned in any appropriate and customary manner. Thepart is then placed as a cathode in an electrolytic cell containing anappropriate chromium electrolyte and the surface (entirely or partiallyas desired) of the part is covered with a layer C of electro-depositedchromium of the desired thickness. Where only a portion of the surfaceof the part is'to be covered with the electro-deposited chromium,appropriate measures well understood in the art of electro-depositionmay be taken to inhibit the electro-deposition of chromium, wheredesired. The wearing part is prepared for chromium plating by cleaningthe surface to be plated in any appropriate manner as, for example, byan acid and alkali dip. The wearing part A is then hung as a cathode ina chromium plating bath, preferably a chromic acid bath containing atable catalytic agent, such as a sulphate radical as set forth in thepatents to Fink 1,581,188, dated April 20, 1926, and 1,802,463, datedApril 28, 1931 and others of Fink and associates. The plate C may beeither a grey or a bright plate, as may be necessary or desired, andsuch plate may be obtained by methods disclosed in said patents.

We claim:

1. In an internal combustion engine the combination of a passage forexhaust gases having a bearing adjacent thereto and a poppet valvearranged to control flow of exhaust gases through said passage andhaving a portion of its stem supported in said bearing and anotherportion exposed in said passage, said stemhaving both said portionscoated with chromium.

2. A poppet valve for internal combustion engines having a guide bearingfor the stem portion, said stem being coated with chromium.

3. A hearing member and a member supported therein for relative movementand frictional engagement therewith, one of said members being

